PC monitors two-way RS-232 transmission


Posted on Jan 14, 2013

The method in Figure 1a needs no access or knowledge of the communicating devices. A C program opens two COM ports and installs interrupt-service routines for IRQ4 and IRQ3. Upon the reception of an interrupt, the routine stores a byte in a common circular buffer with the COM identifier and error flags. The main program displays the contents of the buffer, indicating time intervals in milliseconds between consecutive transfers. Although the program simplifies the time measurement, it preserves the original byte order and correctly reflects time relationships as long as the main program keeps up with transmission speed.



If you need greater precision, you can easily modify the program to record time stamps, along with the data and status bytes, in the circular buffer. Unfortunately, not all PCs offer two COM ports. This deficiency is a common drawback of notebook compu




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Bedwetting (Enuresis) Alarm with 555 timer
Pulse-Width-Modulated Motor-Speed Control Circuit
exponential vf converter for electronic music
12KV High Voltage Generator
supercapacitor usb light
temperature controller using ds1820 and lcd display
Make your own instrumented glove
8W + 8W tube amplifier circuit
L293 reversible motor drive circuit diagram
Darlington phototransistor type light control switch circuit diagram sensitive application



Top